


The Pines Twins vs The Rubber Ruination

by AlexOC



Series: The Pines Twins vs The Trouble Toys [1]
Category: Gravity Falls
Genre: Cursed Sex Toy, Dubious Consent, F/M, Pegging, Sibling Incest, Strap-Ons, magic sex toy
Language: English
Status: Completed
Published: 2017-12-06
Updated: 2017-12-06
Packaged: 2019-02-11 13:04:14
Rating: Explicit
Warnings: Rape/Non-Con, Underage
Chapters: 4
Words: 3,122
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12935880
Author URL: https://archiveofourown.org/users/AlexOC/pseuds/AlexOC
Summary: Home alone, Dipper and Mabel explore the locked attic where Stan stores old Mystery Shack exhibits. Of course fake taxidermy and overpriced bobble-heads are not all the old man has shoved up there to be forgotten...





	1. Buried Treasure

Mabel took a deep breath of musty air and blew hard. Caked layers of dust flew off the top of the box she was holding, filling the confined space of the attic and revealing a worn cardboard box. The corners were dented, the tape holding it shut flaking, and a water stain had ruined the hand written label that now just said:

"Ma-"  
"Toys"

Her brother coughed up the face-full of dust he'd just been blasted with and twisted his head trying to read the label.

"What-" cough "What is it?"

"Magic Toys? Manly Toys? Makeout Toys?" Mabel guessed jokingly as she set the box down on the bare wood floor.

Dipper squared down, leaning over the box as Mabel dug her fingernails into the dried-out tape and tore the lid up. More dust was kicked up and they excitedly peered through the thinking cloud, eager to know what the box held.

It took less than a second before the box was slammed shut again.

They looked at each other blushing furiously; embarrassed, confused, and more curious than either of them wanted to admit.

"That was-" Dipper cut himself off mid sentence. "Not what I expected."

Mabel had other concerns. "Why was it purple Dipper?! And why was it so big! I've seen yours before and they aren't supposed to look like that!"

Dipper blushed a brighter shade of red. They didn't talk about that part of sharing a room, and they especially didn't talk about his you-know-what.

"I-" He stuttered out. "I'm perfectly normal for my age!"

Oh God, why did he say that?

"I mean that just not based on um... It's for adults you know and I guess some adults must really like purple." Dipper glanced back down at the box, now in even rougher shape than before.  
Mabel placed her hand on the lid of the box again. "Should we put it back or..." Her voice trailed off and she left her curiosity unspoken.

Dipper knew her though. "It would be kind of a waste. The store is closed, Grunkle Stan is out of town, and if he realizes we were up here he might fix the lock on the attic door."

They nodded together and Mabel inched the box open again.

The box was piled full of strange devices; leather straps, metal buckles, pieces of oddly shaped rubber, the kind of things kids spread exaggerated rumors about on the playground. And sitting right on top of them all, resting gently on a matching purple velvet cloth, was the dildo.

Mabel let her hand hover over it all for a moment and blanched as she noticed that the purple monstrosity was longer than her entire hand.

Significantly.

That's supposed to go inside someone!

She laughed nervously. "Wow that's a big-".

"-pile of stuff." Dipper blurted out quick. He blushed again. "Sorry"


	2. Playing with Rubber

**Summary for the Chapter:**

> They found more than they bargained for, will they handle it with maturity or all the grace of middle schoolers?  
> And are they prepared for the consequences?

The rain hitting the roof outside was the only sound in the small attic space above the store. The twins let the silence stretch out as they sat frozen and studying the contents of the box.

Mabel shifted uncomfortably. "So you didn't want to hear me say 'dick?"

Dipper's continued blush was absolutely adorable.

"It's weird!" He whined. "You're my sister, you're not supposed to talk about dicks!"

Mabel grabbed the dildo by its flat base and thrust the business end at Dipper, who hopped back in surprise. "Not scared of them, are you?" She laughed.

"Ew, no." Dipper shouted back, joining in the laughter, as he simultaneously tried to bat away her attacks and not touch the dick.

The duel was brought to an end when Dipper was able to open up an old umbrella and use it as a shield. Mabel was forced to admit defeat at the hands of someone not armed with a sword that jiggled if you wave it too hard.

She leaned against a stack of boxes and turned the thing over in her hands, it had a set of thin straps hanging of its base. "What the..."

"Hey Dipper." She called to her brother who was still behind his shield, apparently not sure if he could trust that the duel was actually over. "What do you think these are for?"

He didn't seem as nervous now and gave it a studying look. "I think yo-" a grossed out look in his face told Mabel he wasn't exactly relaxed talking about it either. "I mean a girl is supposed to tied it on like they have their own." He coughed and quickly gestured downwards.

"WHAT! No Way!" She started sorting out the straps, figuring out which ones went where.

"What are you doing?" Dipper was sounding nervous again.

"Trying it on obviously." She turned aways from her brother, saving the big reveal, and tried to center the dick as she hastily tied two straps together behind her back. "This is going to be hilarious!"

She swung back around the purple protrusion loosely attacked at her waist like a oversized belt buckle. It bobbed left and right, the momentum of her swing causing it's rubbery length to whip back and forth.

It was too much and they both started laughing; pushed to the brink of tears when Mabel places her hands on her hips and thrust them at her brother, causing the end of the dildo to bounce up and down as well.

Mabel took a step forward readying to thrust her hips at Dipper again. "I'm coming to get you Dipper."

A crack of thunder shook the roof, the windows rattled and dust was kicked up into the air.

Mabel felt something brushing against the bare skin of her legs and threw her hands down to brush away what her mind was already sure would be dozens of spiders, send scurrying in panic from the noise.

Instead her hand found the straps that had hung from the dildo, alive and writhing beneath her fingers. They thrashed, and twisted, and darted as she tried to yank them off in a panic. Every one slipped through her grasp and wrapped around or between her legs. They grew tight, digging into her and slowly the dildo moved downwards.

Her heart was pounding and panic filled her chest. What was happening?!

"Mabel!" Dipper cried and he rushed towards her, only to freeze with his hand outstretched, a horrified look on his face.

Mabel looked down at the pile of shredded cloth at her feet. The crisscross of straps had sliced through her clothes leaving her naked from the waist down. A panicked gasping over took her breaths and she looked around the room in desperation, there had to be a something to get this thing off.

The purple monstrosity shifted a final inch, dragging its cold rubber form on top of her clitoris. The feeling of a foreign body forcedly manipulating her down there shocking and disturbing.

She was reaching to grab the thing and tear it off when it stopped.

It stopped moving and pure bliss filled her.

A steady purr took hold between Mabel's legs and resonated up through her, echoing around inside her head.

Her heart slowed to rhythmic beat, steady and powerful. She was left light headed as blood rushed to her extremities, every inch of her skin flush and sensitive. A thin sheen of moisture started to flow from between her legs and she gently gently bit her lower lip, trying to hold herself back.

She took a deep breath, feeling the rough wool of her sweater drag across her erect nipples. Exhaling was like a breath of wind carrying everything away; all the fear and panic, the confusion and reservation. She felt like she could do anything.

Dipper had covered his face with his hands and turned away embarrassed at her display. He didn't know how good this felt, how there was nothing to fear in this much pleasure.

She ran a gentle finger down the length of the "toy" that had changed her world; somehow she could feel her touch on the rubber and it was good. Not that she didn't enjoy herself, but if it was this easy she could see why Dipper had so much alone time.

Her fingers slid off the base of the shaft and unable to reach her clit, Mabel went lower and lightly fingered herself. She smirked as her deep moan of pleasure made Dipper jump.

"Mabel please! Something's wrong!" Dipper turned, tried to look at her, plead with her, but the words fell on deaf ears and he stumbled back as she advanced.

Mabel put a pair of moist fingers on his chest and he froze like a deer in headlights. Her fingers inched down his torso, pausing only briefly to lift his shirt and she reached down beneath his waistband.

Her fingers brushed past a scant scattering of hairs and she wrapped her hand around her brother's dick. It was a bit too long to fit in the palm of her closed hand and an entirely too normal piece of equipment for a boy his age, nothing like the thing strapped to her hips. But that didn't really matter, it was hard and from the way Dipper was squirming he was loving it.

She smiled. "Dipper Pines, you are a dirty boy."

She played with him, rolling and caressing his dick inside his shorts, enjoying his expression as he tried to stop the little squeaks and moans of pleasure from escaping.

Her free hand found its way beneath his vest and she forced her tongue into his mouth in a wet kiss that left Dipper's vest on the floor and Mabel's hand exploring underneath his shirt...

She was unstoppable, a trail of discarded clothes left Dipper in only unbuttoned shorts when Mabel pushed him half seated against a box in the attic, the tent in his white briefs poking through.

She lay her hands against his chest, feeling his heartbeating against them and pressed him down on top of the box. It was barely large enough for him, supporting only his chest while his waist dangled off the edge and his head was only held up by his need to watch her. Hands trembling with excitement she gripped his shorts in both hands and lifting his legs up in the air, pulled them off her brother.

His dick practically sprung free of his briefs as she stripped him naked. Mostly hairless and only a few inches long, it still had a dribble of precum coming from the half peeled back tip. It was a cute toy.

Not caring where they landed, Mabel threw the last of Dipper's clothes off into the attic and bore down on him again. She grabbed up his dick and her dildo in one hand, wrapping and squeezing them together. His skin was burning hot, blood pounding through it and they moaned together as she pumped her hand. Up and down, rough, uncaring; she moved her hand with the vigor of someone without limits.

Dipper moaned, his voice filling the small space, and squeezed hard, holding them both right on the edge. Her hand was moist as she drew it back, beads of some strange lubricant had begun to form on the rubber.

"Not yet..." She said. Half teasing, half chiding.

She was enjoying herself, but a sweet tension inside her sung out for more. The muscles in her abdomen ached longing for release, but it wasn't right yet.

Her eyes roamed the naked, panting body of her younger brother; there had to be a way to sate her needs, the fire burning in her breast, a hole that needed to be filled...

Of course.

She pulled back, separating them, and bent her knees just a little, lowering herself a few inches. Dipper's legs were spread wide and it was easy to find what she was looking for.

"What are you doing Mabel?" Dipper asked, a nervous, almost hysterical laugh threading his voice as she leaned down over him.

He flicked as she guided the slick length forward, his cheeks spreading, and pressed its tip against his taut asshole. She rollee her hips and pressed harder against him, leaning down over the table and supporting herself with hands pressed down on his shoulders.

"Something bad." She whispered, barely heard over his gasping breaths as it penetrated him.

As she penetrated him.

It was better than she'd imagined, the warmth of his body engulfed her an inch at a time. How he writhed against her, the tightness of him as his insides open up to her, the expanding and contracting of muscles inside him; each part of it wrung a unique pleasure from her new rubber friend.

Mabel thrust her hips forward, pushing herself as deeply into her brother as she could. He let out a gasp, his eyes going wide as she struck something inside him and the length of her ground along it.

She pulled back, the worry that she'd hurt him clearing her head. But the glazed look in his eyes and long, high, ragged delighted breath that Dipper let out made it obvious he was far from in pain.

So naturally she did it again.

Slowly at first, she worked herself into a rhythm, each time pulling as far back as she could without pulling out and then plunged back into him, experiencing all the pleasure of diving headlong into his warmth over and over. Dipper barely had time to take a breath before she'd hot that magical spot again and he would let out another moan.

Still she pushed herself harder. Dipper's knuckles were white where he held onto the edge of the box, and her legs burned with the effort of it all. Sweat bloomed on her skin and the air in the room felt thicker with every breath.

They came together, Dipper's whole body clamping down on her as his muscles contracted and he shot a stream of something pale but clear across his bare chest.

At the same time her nerves exploded inside her. Shockwaves of pure ecstasy starting in that tight, slick, warmth that she'd found inside him and burning through her. It raced along every inch of skin, muscles clamping down on themselves, losing pent up energy, or just collapsing all together overstimulated as they were.

It was probably the thunderclap that rattled the windows and woke up a sleeping Waddles on the other side of the shack.

Probably.


	3. Aftermath

**Summary for the Chapter:**

> Did she really just do that?  
> Yes, now she has to deal with the consequences.

Collapsed on top of Dipper, sweat and other fluids soaking her sweater, the rising and falling of his chest calming her; Mabel started to come back to herself.

She wasn't the person that had done...

God what did you even call what she had done to him?

She was sweaty, and sticky, and just plain exhausted. But she was Mabel again.

She rolled off him and onto her back, the wooden planks of the attic floor rough on her naked skin.

Something was thumping its way up into the attic and Dipper was still moaning beside her, but she was so tired and her eyelids started to droop.

A hot, wet pig tongue slapped into the side of her face and with a big slupp licked her.

"GAHH!" Mabel bolted up into a seated position. "Waddles!"

The pig gave her a worried look from where he sad next to her and she couldn't help but feel a little better as she gave him a big hug.

The quiet, sane moment was interrupted by Dipper moaning in pleasure. A noise that, now she wasn't hornier that your average highschool football team, was firmly in the category of things you don't want to hear your sibling make.

She spun to look at him and kept right on spinning as she got an eye full of his very prominent enjoyment of whatever was still happening to him.

"Eeewww" Mabel shuddered. Well, that was going to keep her up at night.

She stared down at the torn up ruins of her sweater, any of her cloth that had hung lower than her stomach had been cut away by the straps, and realized something. It was gone!

She glanced around worried. How alive was that thing? Could it have just fallen off? Could it crawl away?

She took a deep breath trying not to freak out. First things first, find that stupid fake dick and lock back in its box.

Shielding her eyes from Dipper with one hand, Mabel worked her way around the room. Checking behind boxes, pulling sheets off old exhibits, and getting down on her knees to look under broken furniture; all of which was significantly less fun half naked and searching for an possessed sex toy.

She was not that lucky.

Extremely reluctantly she turned back to the last place she'd seen the damn thing, a still quite happy Dipper.

What came next required two beach towels, a pair of rubber gloves, the BBQ tongs, and four Waddles hugs.

Eventually it was done. The box buried back in the attic, as much piled on top of it as she could lift. Its dozens of other things, names unknown to her, safely locked away. The scraps of her clothing were collected and thrown away, cut up for an art project if Grunkle Stan asked, and everything else used in the cleanup buried in the backyard.

They had both needed long long showers; but eventually, still not able to meet each other's eyes, they went to bed.


	4. Epilogue

**Summary for the Chapter:**

> Some things you can't ignore...

"Going to bed" was about as generously as you could call Mabel's attempt to fall asleep. She could hear Dipper twisted and turning, constantly adjusting his sheets. While she couldn't seem to stop herself from reaching beneath her pajamas to finger the bruises the straps had left in her skin.

Touching them made her want to do thing, like that thing had left a spark in her ready to flare up if paid any attention. It was humiliating. She didn't want to be here, she didn't want the reminder of what had just happened, she didn't want to think about how good it had all felt... But she couldn't just leave, Dipper had to feel bad enough without her ditching him too.

She rolled over, keeping her hands on top the covers and trying to get the images of whips, gags, strange locking tubes, a dozen other multi colored devices, out of her head.

"Fuck." A exasperated voice spat from the other side of the room.

Dipper's sheets rustled again and in the dark she could just make out him sitting up to look at her. 

"I can't get the blue one out of my head!"

Mabel felt her heart speed up at his words.

Grunkle Stan wasn’t going to be home until Monday.


End file.
